(i) Field of the Invention
This invention relates to a method and apparatus for transporting a plurality of like objects having a substantially uniform size and, more particularly, relates to a method and a conveyor and escalator apparatus for transporting eggs and the like objects.
(ii) Description of the Related Art
Egg conveyors form an essential element in a typical egg collection apparatus. A typical egg collection system has a main conveyor for receiving eggs from a nest ancillary conveyors for delivering the eggs for further processing, and a packing machine for packaging the eggs.
Transferring the eggs between different handling apparatus involves a succession of transfer points with each successive transfer point increasing the likelihood of damage to the eggs, which can significantly decrease the productivity of the operation. Present systems involve numerous transfer points because of the number of different handling apparatus.
The conveyors of the prior art systems rely on gravity to retain the eggs on the conveyor surface. In order to change the direction or elevation of the egg path, the eggs must be transferred to an elevator or inclined belt conveyor, and then usually transferred back to another conveyor, not only increasing the number of transfer points and risk of damage to the eggs but also requiring a large working space in which to handle the eggs.
U.S. Pat. No. 5,279,254 (Dowty) issued Jan. 18, 1994, U.S. Pat. No. 4,345,682 (White et al.) issued Aug. 24, 1992, U.S. Pat. No. 3,672,485 (Walters) issued Jun. 27, 1972, U.S. Pat. No. 3,626,905 (Mombris et al.) issued Dec. 14, 1971, U.S. Pat. No. 3,166,175 (Kurtz et al.) issued Jan. 19, 1965, and Canadian Patent Application Serial No. 2,002,588 laid open on May 11, 1990, disclose egg collecting systems having a conveyor belt for transferring eggs to an elevator which transfers eggs to a cross-conveyor.
U.S. Pat. No. 5,365,717 (McKinlay) issued Nov. 22, 1994 discloses open baskets mounted on a continuous conveyor which move from an upright loading position to an inverted unloading position for discharge into a loading chute and delivery into egg flats. U.S. Pat. No. 3,166,175 (Kurtz et al.) issued Jan. 19, 1965 discloses an egg collection and elevator conveyor system which comprises egg flights consisting of equispaced parallel bars forming elongated open pockets which support eggs thereon by rearwardly tilting of the open pockets on an elevator and which discharge eggs by forwardly tilting the pockets downwardly.
All these patents use multiple conveyor systems in combination with elevator systems for transferring eggs between conveyors located at different elevations. These systems have an increased likelihood of damage to the eggs because of the plurality of transfer points between the different handling apparatus. Additionally, these systems are relatively complex and thus expensive to manufacture and to maintain.
The disadvantages of the prior art may be substantially overcome by providing a novel conveyor and escalator for transporting eggs and the like which obviates or mitigates at least one disadvantage of the prior art.
It is a principal object of the invention to provide a conveyor and escalator for transporting objects having a substantially uniform size and shape, such as chicken eggs, with a minimum of transfer points in a reduced working space.
Another object of the invention is the provision of a conveyor and escalator which can elevate eggs vertically upwardly or downwardly from one level to another and can change the direction of travel of the eggs during vertical travel.
A further object of the invention is to provide a conveyor and escalator that is relatively simple in construction, inexpensive to maintain, and substantially trouble-free in operation to safely transport eggs with minimum breakage.
According to a first aspect of the present invention, there is provided a conveyor system for transporting like objects having a substantially uniform size and shape. The conveyor system may have a pair of endless chains mounted in a spaced parallel relation with each other with a drive operably engaging the endless chains for synchronously driving the endless chains. A plurality of spaced paddles are rigidly connected to and extend between the endless chains. The paddles are equi-spaced for defining a receiving volume therebetween with adjacent upper and lower supports for receiving and supporting like objects. The paddles have a closed condition when travelling substantially linearly and an open condition when travelling arcuately, urging the adjacent upper supports to move apart allowing the like objects to pass therebetween into the receiving volume during downward arcuate travel and urging the adjacent lower supports to move apart allowing the like objects to pass therebetween out of the receiving volume. A plate preferably is selectively placed to cooperate with the spaced paddles for closing the receiving volume to retain like objects within the receiving volume when the paddles are travelling arcuately in an inverted condition.
In its broad aspect, the conveyor and escalator for transporting objects having a substantially uniform size and length comprises at least one flexible endless support means; a drive means operably engaging said flexible endless support means for driving said flexible endless support means in a direction of advance; and a plurality of equispaced elongated paddles attached substantially perpendicular to said flexible endless support means, for defining a receiving volume therebetween which closes during linear travel to contain an object in the receiving volume or support the object on the paddles, and which opens during arcuate travel to receive or release an object contained in the receiving volume or supported on the paddles. The endless flexible support means comprises an endless chain, an endless belt or an endless cable. The endless flexible support means preferably comprises a pair of parallel spaced-apart endless chains and at least two linearly-spaced sprocket wheels engaging each said endless chain for supporting said chain in linear travel between the sprocket wheels and in arcuate travel about said sprocket wheels, and means for rotating said sprocket wheels for advancing the endless chains.
Preferably said elongated paddles have an I-section and means at opposite ends of the I-section for removably connecting said paddles at said opposite ends to the endless chains transversely to the said direction of advance. Each paddle comprises an elongated web having longitudinal side edges and a flange having an inner face attached centrally along said face to each longitudinal edge of the web to form an I-section having a longitudinal central axis, means at opposite ends of the I-section for removably connecting said paddles at opposite ends to the endless chains at said longitudinal central axis transversely to the endless chains and perpendicular to the endless chains whereby the paddles remain vertically upright during horizontal linear travel to support objects on adjacent upper flanges and whereby the paddles pivot relative to each other about said longitudinal central axis during arcuate travel to open adjacent paddles at the upper flanges to receive objects therebetween during downward arcuate travel and to open adjacent paddles at adjacent lower flanges to discharge objects therefrom during upward arcuate travel. Each paddle may comprise an elongated web having an arcuate flange with a concave inner face attached centrally along each said face to said longitudinal edge of the web to form an I-section having a longitudinal central axis, and an end plate having a pair or upstanding spaced-apart fingers at each end adapted to receive the paddle web therebetween and to engage the concave inner face of the adjacent arcuate flange, and means formed centrally on the end plates for rigidly connecting each of the end plate transversely to the endless chains perpendicular thereto.
The paddles optionally may have a C-shaped cross-section, a Z-shaped cross-section, an inverted J-shaped cross-section, or an inverted T-shaped cross-section or an inverted 7-shaped cross-section.